1985 K100 requiring Leaded Gasoline?

[MichaelMandel]

So can you all share your thoughts on this "little" bit of info I just stumpled upon after riding my bike fro months and replacing the water and oil/water pump yesterday.  I can't believe I just stumbled upon this.

I've been running 87 unleaded with marvel mystery oil.

Do I need a lead additive or replacement?

What do you all say?

[Laitch]

The engine was designed to run on unleaded. Using a lead additive contributes to pollution, is a waste of money and could foul the works.

Running ethanol-free fuel might help keep the fuel system from gumming up on a bike that is rarely run. My experience tells me the best way to treat my bike is to ride it often, for long distances, rain or shine, with fresh fuel graded ≤10% ethanol in mid or high octane, and with a smile on my face.

I used MMO in my VW boxers through the seventies. Why was the mystery. I still needed to adjust the valves, adjust the points gap, adjust the timing, change the oil and clean the oil screen every 3K or else deal with burnt valves—all that for a low-powered vehicle with a heater that had the warming power of a hyperventilating bunny's breath; however, the 35mpg was nice and fuel was only $0.50–0.75 per gal.

[The Mighty Gryphon]

VW boxers!!!  AKA "Hitler's Revenge".  Had 7 or 8 of them including two buses.  What the F was I thinking?!  The heater was designed to toughen up the German people for the next Russian invasion, and the body was only rated to last six months before it rotted out.  The clutch cable broke every February on the coldest day of the winter when it iced up in the tube it ran in under the floor.  Coming down a hill at 55 my bus blew the pistons out of the rear wheel cylinder.  If you did the biweekly oil change and valve adjustment, you might get one to go 50k before it blew cylinder #3.  But they were somehow popular with us drug addled hippies of the 60's and early 70's.  A real tribute to the power of reefer to overcome common sense.

[MichaelMandel]

The engine was designed to run on unleaded. Using a lead additive contributes to pollution, is a waste of money and could foul the works.

Running ethanol-free fuel might help keep the fuel system from gumming up on a bike that is rarely run. My experience tells me the best way to treat my bike is to ride it often, for long distances, rain or shine, with fresh fuel graded ≤10% ethanol in mid or high octane, and with a smile on my face.

I used MMO in my VW boxers through the seventies. Why was the mystery. I still needed to adjust the valves, adjust the points gap, adjust the timing, change the oil and clean the oil screen every 3K or else deal with burnt valves—all that for a low-powered vehicle with a heater that had the warming power of a hyperventilating bunny's breath; however, the 35mpg was nice and fuel was only $0.50–0.75 per gal.

Thanks for the straightforward response.

I have never had any experience with this bike before a month ago.  I got this 85 k100 for free so I've been working on it little by little to keep it happy since I've read people taking them to 390xxx.  Mines got 40k, I just replaced the water/oil pump and it starts up on first pop and runs like new. I mean the bike to the right for a few seconds before putting it on side stand and there's no smoke at startup.  Came with a sweet rear öhlins suspension too.  Stripped around 80 pounds of plastics and brackets off and popped a nice bright LED headlight on it.  Can't wait to ride this bike through the years.  I ride bikes every day, unless my two year old is with me, they are my main mode of transportation on these windy Topanga CA roads and I truly feel blessed for this "new to me" year round riding environment.

If there are any things you think I might know or be on top of please let me know.
Thanks.

VW boxers!!!  AKA "Hitler's Revenge".  Had 7 or 8 of them including two buses.  What the F was I thinking?!  The heater was designed to toughen up the German people for the next Russian invasion, and the body was only rated to last six months before it rotted out.  The clutch cable broke every February on the coldest day of the winter when it iced up in the tube it ran in under the floor.  Coming down a hill at 55 my bus blew the pistons out of the rear wheel cylinder.  If you did the biweekly oil change and valve adjustment, you might get one to go 50k before it blew cylinder #3.  But they were somehow popular with us drug addled hippies of the 60's and early 70's.  A real tribute to the power of reefer to overcome common sense.